Some vector graphics techniques use a “painter model” for rendering. When using a painter model, objects are rendered one over another (in a manner that may be thought of as layering). For example, a first object is rendered, and then a subsequent object is rendered, possibly partially overlaying and possibly obscuring the first object. Objects may be defined in a graphics file in a manner that specifies the arrangement or order of the objects in a rendered display. For example, objects defined at the beginning of the graphics file may be rendered first (and are therefore at the back or lower layers of the rendered display) and objects at the end of the graphics file may be rendered last (and therefore at the front or upper layers of the rendered display).
In order to detect user events, a graphics file may include an event capture object. The event capture object may detect user interaction events, such as mouse over events. The event capture object may be used to highlight regions of a rendered display by triggering execution of code that causes the event capture object or another object to be modified in the rendered display. Methods of highlighting objects in a painter model rendered display can be less than satisfactory because the order in which the objects are layered in the rendered display can lead to highlighting that does not behave as users expect. Further, a graphics file that includes data to enable highlighting of objects in a rendered display can be very large as a result of the amount of data used to define multiple objects, to link the objects to enable highlighting, and to provide executable code to implement highlighting based on user events.